It was perfect Until It Wasn't - Pins

Bob La Londe · 2026-05-31T20:42:49+00:00

Through all my headaches setting pins yesterday I managed to keep the machine from moving. The vise I used to machine the vises measured within a couple tenths of parallel to travel. I locked one axis, and then put a cheater bar on the handle to make sure it wouldn't move.I left the pins set overnight so the Loctite 604 could cure, and this morning I dropped them on the machine where they are going. Both vise pins bumped up against the planned t-slot and both vises were within were less than a thousand pout of parallel to the travel of the machine. Pretty darn good when you consider I have never indicated that t-slot and had no idea how straight it was. Then I found the problem. The two vises are 7 thousandths out of line with each other. DANG-IT!I checked the original factory face, and I check the machined step I put in the jaws. Both were straight, and both were 7 thousandths out of line with the other vise. They were both parallel. Just .007 out of line with each other.I was pretty careful with the setup, but the body of the vise was supported by the fixed jaw in the vise holding it while I drilled the pin holes. It was a lot more rigid than it sounds. Under all the forces the DRO never drifted. Well, 0.0002, but that doesn't really count.I have two ideas for the discrepancy.1. I got a chip in the setup somewhere or made some other mistake that put them 0.007 out of line, but kept it parallel.2. The fixed jaws of the two vises are .007 difference in thickness. from front to back.Sorry, can't check it right now. As soon as I got over my temper tantrum I lined up the two vises with hammer, cinched them down, and threw a fixture plate in them to start roughing mold blanks 4 pieces at a time.Maybe tomorrow I'll pull the fixture plate out of the way and measure the jaws.What do you think happened.1. Did I screw up by a nice parallel 0.007 inches?2. Did the Chinese grinder operator just stop when the vise was square without checking all the...

May 31, 2026 Last reply: 1 month ago 21 Replies

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Bob La Londe 1 month ago

Remember Snap N Pops. You could make a whole bombing run with those. Not as loud as some paper caps, but loud enough.

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Jim Wilkins 1 month ago

Remember Snap N Pops. You could make a whole bombing run with those. Not as loud as some paper caps, but loud enough.

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